Reproductive Anatomy Flashcards
The Ovary
- solid ellipsoid organ
- follicles containing a single ovum
- loose vascular zone, medulla in centre
- opposite in horses (because horses are cunts <3)
Follicle Production
1) Primordial Follicle; single layer of flat granulosa cells
2) Primary Follicle; flat granulosa cells —> cuboidal cells
3) Secondary follicle; several layers of cells with fluid-filled spaces
4) Tertiary Follicle; mature, fluid spaces joint up
Follicle Development (post-maturity)
1) Tertiary follicle ruptures; ovulation. Fluid flushes ovum to uterine tube
2) Remaining follicle tissue bleeds a little
3) Proliferation of tissue to form corpus luteum
4) If NOT pregnant CL regresses, scar tissue forms the corpus albicans
Hormones involved in ovulation and CL maintenance
- FSH and LH; ovulation
- Progesterone; persistent CL
- PGF2(alpha); regression of CL
The Uterine Tube
AKA oviducts
- capture and transport ova to the uterus; usually the site of fertilisation
- lined by ciliated epithelium
- Expanded near ovary into the infundibulum
- ampulla makes up the middle section
- isthmus is the narrow portion
The Uterus
- comprised of horns, body and cervix
- cervix limits access from the vagina
- cervical mucosa produce mucus, creating a plug
- uterine wall has 3 layers
3 layers of the uterine wall
- mucosal layer (endometrium); thickness varies with oestrus cycle, numerous tubular glands. Ruminants have uterine caruncles
- muscle layer (myometrium); smooth involuntary muscle responsible for uterine contractions
- serosal layer; (perimetrium); outer surface, continuous from the broad ligament
The Vagina, Vestibule and Vulva
- vagina and vestibule form the whole rest of the internal tract
- Vagina is cranial, purely reproductive passage
- Vestibule caudally from urethra to external vulva
Ligaments
- The broad ligament; suspending tract from dorsal body wall
- Broad ligament also encloses blood vessels, nerves and some other ligaments
- Intercornual ligament; connects the uterine horns
Broad Ligament
Connected to…
- ovary; mesovarium
- uterine tube; mesosalpinx
- uterus; mesometrium
- cervix
The Ovarian Bursa
- Folding of the mesovarium and mesosalpinx creates a pouch
- communicates with peritoneal space
- can contain fat
The Testis
- coiled tubes; seminiferous tubules are the site of sperm production
- these tubules are open loops into the network in the testicular mediastinum called the rete testis
- Rete testis drains into the head of the epididymus
Spermatogenesis
- producing sperm cells
- produced in the epithelium of seminiferous tubules
- supported by the Sertoli cells
- Leydig cells responsible for testosterone secretion
Testicular blood supply
- the branches of the testicular artery and vein run with the tunica albuginea, covered by visceral layer of tunica vaginalis
- the veins form the pampiniform plexus; wrap around the artery many times; pre-cools blood entering testes
- testicular artery is a direct branch of the abdominal aorta
Spermatic cord
A collection of structures…
- Testicular vein, artery, nerves and lymphatic vessels
- Deferent duct
- Visceral and Parietal vaginal tunic
Bound together by spermatic fascia
- Cremaster muscle; portion of internal abdominal oblique, runs alongside spermatic fascia inserts into cranial pole of the testes
Testes temperature maintenance
- Pampiniform plexus pre-cools blood
- Many sweat glands in scrotal skin
- If too cold, cremaster muscle contracts to pull testes closer to the body
Male sex glands
- Ampulla; enlargements at end of deferent duct
- Vesicular; near opening of deferent duct
- Prostate; in all domestic species
- Bulbourethral glands; near urethras exit from the pelvis
The Penis
- Normally contained within the fold of skin called the prepuce
- ROOT; originates from ischial arch
- BODY; corpus cavernosa combine run alongside corpus spongiosa
- GLANS; distal free portion
Penis Structure
- 3 columns of cavernous erectile tissue
- paired corpus cavernosum, separated by a septum
- unpaired corpus spongiosum; surrounds urethra
Types of penis
- Musculocavernous; (horse, dog, cat, human); erection achieved by large volumes of blood filling the blood spaces
- Fibroelastic; (ruminants and pigs); penis is inherently stiff. Elongation of penis is caused by relaxation of the retractor muscle & straightening the sigmoid flexure
Muscles of the penis
- Retractor muscles; paired originate from caudal vertebrae, smooth involuntary muscle
- Bulbospongiosus; continuation of urethralis muscle, expels urethral contents
- Ischiocavernosi; paired, enclose the crura. Upon contraction, block venous return from corpus cavernosum
Blood supply to the penis
- Internal pudendal artery; splits into 3…
- artery of the bulb of the penis
- deep artery of the penis
- dorsal artery of the penis
